Pliers for bending metal pipe.



No. 83l ,356. PATBNTED SEPT.18, 190

I. KOBER.

PLIERS FOR BENDING METAL PIPE. APPLICATION nun APRJ). 1906.

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HIIHIH I H UNITED STATES PATENT OFFICE.

PLIERS FOR BENDING METAL PIPE.

Specification of Letters Patent.

Patented Sept. 18, 1906.

Application filed April 9, 1906. Serial No. 310,634,,

fers from pliers of the known kind in which at the bend the material inexcess is forced into the inner side of the pipe by means of a bladefixed on one of the arms of-the pliers,

owing to the fact that in place of this single blade two or more of halfthe size are arranged opposite but laterally displaced relatively toeach other in such a manner as to be positively displaceable. Owing tothe division of the blade into two parts and their lateral displacementrelatively to each other, the danger of fracture of the pipe where it ispressed in is largely reduced as compared with the constructionshitherto employed, as the indentation formed by one blade amounts toonly about one-fourth of the periphery of the pipe, while with the knownconstruction it extends over about one-half the periphery of the pipe.Accordingly a pipe bent by means of the tool in accordance with thisinvention will be far stronger than a pipe bent with the known form oftool. The bladejaws are formed and fixed in such a way that any lateralgive of the pipe to be bent is obviated. Further, a set-screw isprovided on the pliers which screw prevents the pliers from beingpressed together beyond the amount appropriate for the size of pipewhich is being acted upon. This positive adjustment of the blades andminimum width of jaw present the further advantage that the tool may beutilized for any thickness of pipe and for any desired curvature, for byopening the blade-jaws wider than corresponds to the pipe to be bent asmaller bending of the pipe is obtained than when the jaws are exactlyadjusted to the diameter of the pipe, while owing to the adjustabilityof the width of jaw the blades are prevented from cutting too deeplyinto the pipe. The other half of the pliers is provided with projectionswhich serve as supports for the pipe to be bent and which, if desired,may be positively displaceable.

In the accompanying drawings, Figure 1 represents the pliers in frontelevation. Fig. 2 is a section of the same through the bladeadjustingdevice. Fig. 3 shows the pliers in side elevation. Fig. 4 represents aninsulating-pipe with indentations formed by the tool.

The pliers consists of the two two-armed levers a and 1). Into the upperend of a, a casing 0, open in front, is let, its upper wall 01 beingfixed only after the blade-jaws e have been arranged in position. Theupper and lower walls of this casing serve for holding the set-screw ffor the blade-jaws, while the casing itself serves to guide theblade-jaws. These jaws are provided at their rear part, which serves fortheir guidance, with right and left handed screw-threads, respectively,

in which the set-screw furnished with corre sponding threads engage sothat by rotating the screw the jaws are caused to approach or recedefrom each other. In its front portion, but not at the middle of thesame, each of the jaws e presents one or more recesses into which bladesare fitted, these blades presenting a cutting edge which approximatelycorresponds to the diameter of the pipe, being so shaped that it isimpossible for the pipe to be bent to give laterally. The blades areinserted in the opposite jaws with a relative lateral displacement, sothat a recess 9 must be provided in each aw for each blade facing thesaid aw, this recess serving for the reception of the projecting part ofthe opposite blade when the jaws are screwed together. The upper end ofbis provided with two projections 7L, lying symmetrically to the middleof. the pliers and, if desired, positively displaceable, theseprojections being bent so as to approximately correspond to the diameterof the insulating-pipe to be bent for the purpose of more securelyholding this pipe. The jaw may be adjusted for a minimum width by theset-screw i, carried through one of the levers of the pliers.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is

1. In a device of the character described, a casing carried by onemember of the pliers, blades mounted in said casing and adapted to belaterally displaced relatively to each other, and means for adjustingsaid blades.

2. In a device of the character described, a casing carried by onemember of the pliers,

blades mounted in said casing and adapted to be laterally displacedrelatively to each other, means for adjusting said blades, andprojections carried by the other member coacting with said blades.

3. In a device of the character described, a casing carried by onemember of the pliers, jaws mounted in said casing, means for adjustingsaid jaws, blades having curved faces carried by said jaws, andprojections on the other member of the pliers.

4. In a device of the character described, a casing carried by onemember of the pliers,

blades mounted in said casing and adapted to be laterally displacedrelatively to each I5 other, means for adjusting said blades, and meanswhereby the pliers may be set for a minimum width.

In testimony whereof I have hereunto set my hand, in presence of twosubscribing wit- 2o nesses, this 21st day of March, 1906.

FRITZ KOBER.

Witnesses:

M. O. DILLINGHAM, MAX SCI-IUSTER.

